paige_pharma said:Mass spectrometry confirmation for certificates of analysis: beyond HPLC purity, mass spec tells you the molecule's exact molecular weight.
Same pattern here, and in the same order. Nothing to add that would improve it.
josh_phd_bmore said:Vendor quality matters when discussing certificates of analysis.
Second this. I had assumed I was the exception until I read this.
josh_phd_bmore said:Vendor quality matters when discussing certificates of analysis.
COA red flags for certificates of analysis — here's what to look for when reviewing a Certificate of Analysis:
- No HPLC data: If there's no chromatography graph, it's not a real COA
- Exact 100% purity: Suspicious — real testing always shows slight variation
- No batch number: Can't trace back to specific production
- No endotoxin testing: For injectables, this is essential
- Template looks like it was made in Word: Professional labs have standardized formats
I have seen fake COAs that are literally photoshopped. Always verify independently if possible.
Sigma-Aldrich — Research-Grade Standards
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Shop Reference Standardsjosh_phd_bmore said:Vendor quality matters when discussing certificates of analysis.
Community-verified vendors for certificates of analysis: I maintain a spreadsheet of Janoshik-verified test results submitted by community members. Across 47 submitted tests:
- 75% tested at ≥98% purity
- 18% tested at 95-98% purity
- 7% tested at <95% purity (concerning)
The vendors with consistently high purity results are listed in the Vendor Directory. We update monthly based on new community submissions.